1. Field of the Invention
The present invention relates to a dental crown polishing apparatus for polishing dental crowns and the like.
2. Description of the Related Art
Dental crowns, bridges, dentures and the like (hereinafter referred to collectively as “crowns”) are produced in a dental crown laboratory. Typically, crowns are polished in the finishing stage. The crowns are machined to a complicated, uneven shape so as to give them the same capabilities as a natural tooth.
In the conventional polishing step, as shown in FIG. 11, a dental lathe or a hand piece 100 (hereinafter “hand piece or the like”) is used and each crown 110 is polished individually by hand. In general, the hand piece or the like 100 is mounted with a disc-like polishing brush 102 disposed on a rotary shaft 101. The disc-like polishing brush 102 is so large compared to the size of the deeply uneven surface of the crown 110 that the deep grooves can not be polished precisely without breaking the crown 110.
The inventor of the present invention previously invented an orbital dental crown polishing device equipped with small brushes adequate to the task of polishing crowns one at a time, as disclosed in Japanese Laid-Open Patent Application Publication No. 2003-048145 (“Pat. Pub. No. 2003-048145”). FIG. 12 shows a side view of the device disclosed in Pat. Pub. No. 2003-048145. As shown in FIG. 12, a brush 151 is contact with the uneven surface of a crown 160 and the crown 160 is moved manually while a device 150 supplies fluid containing a polishing agent (polishing slurry) to the brush 151 so as to polish the surface of the crown 160. The apparatus 150 makes precise polishing of the crown 160 possible without damaging it.
However, the apparatus disclosed in Pat. Pub. No. 2003-048145 has room for further improvement. In particular, since it is necessary to hold each crown in hand and polish it, a great deal of time is required to polish many crowns, and consequently the cost of processing the crowns increases.